1. Field of the Invention:
The present invention relates to monitoring devices for optical fibers. More particularly, the present invention relates to taps on optical fibers for monitoring the transmission of fiber optic signals.
2. Discussion of Background:
Devices and methods for monitoring the transmission of fiber optic signals are well known. Furthermore, taps on fiber optic cables for purposes of monitoring optical transmission are known. With a typical fiber optic tap, a predetermined fraction of light from an optical fiber is diverted from the fiber and directed to a photodetector or other light conversion device. Fink, et al (U.S. Pat. No. 4,678,265), and Kahn (U.S. Pat. No. 4,475,789) disclose fiber optic taps for monitoring purposes. Fink, et al use a fiber optic plug device that converts optical signals into electrical signals for monitoring the intensity of an optical transmitter. Kahn discloses a splicing configuration and the use of a photodetector to monitor optical signals in a fiber.
The use of light display elements in conjunction with fiber optic taps is also known. In addition to photodetectors, LEDs, and the like, lenses have also been used (see U.S. Pat. No. 4,475,789, col. 3, lines 29+ and U.S. Pat. No. 4,081,672, col. 2, lines 64+). However, the lenses used in the prior art converge or focus light or direct it to the input of other devices for processing or display.
Nothing in these references teaches a device or method that provides monitoring from the diverted fraction of the fiber optic signal in a way that can be readily observed by the unaided human eye. There exists a need for such a device for rapid monitoring of fiber optic transmissions.